TEFCO ENGINEERING PTY LIMITED ABN 35 054 554 611 CONVEYOR PULLEY CAPABILITY DESIGN Tefco uses a number of design philosophies for the various elements that make up a modern live shaft pulley, dependent on type of pulley and the loads it operates under. Tefco has in house staff capable of designing conveyor pulleys, sheaves, bearing housings, winches, couplings and locking assemblies of every type and description and also employs Mechanical Engineers with solid modelling, CAD and Finite Element Analysis capability to assist with component design. Shaft: We use AS1403 for shaft design which has been found to be a safe conservative tool for shaft design. We use the recommended Fs value of 1.2. Our K factor used is based on the calculated interference developed by the locking assembly which is dependent on the surface pressure induced by the tightening torque. The K factor is also significantly influenced by the UTS of the shaft material used and we use K1045 as standard with a stress limit of 270Mpa under all load conditions (45% of 600Mpa UTS). The use of other higher tensile materials such as 4140 does not generally give an advantage despite the higher allowable stress limit of 360Mpa (45% OF 800Mpa UTS) because the resultant higher K factor often produces a worse outcome for the same size. Generally we try to reduce the tightening toque to the equivalent of a grade 8.8 bolt despite using grade 12.9 bolts, which minimises the induced stress. Drive pulley locking assemblies are sized to ensure minimum transmitted torque capability of 2 x motor FLT. The shaft deflection is limited to less than 5 minutes under ALL load conditions. Locking Assemblies: We generally use TAS or equivalent such as MAV or Bikon locking assemblies made in Europe. The series used depends on the loads and torque requirements, but as a rule we use the T3006 self centring series unless toque or bending moment requirements need a higher capacity where we will use the wider T3015 self centring series. For both these series we limit the allowable running bending moment thru the joint to 35% of the catalogue rating on drives and 45% for non drives. Bearings & Housings: Once a shaft diameter has been determined we use ISO 281 to check the bearings theoretical B10 life. Housing type used is a function of diameter and client preference, but as a rule we use SNG500 series up to 90 diameter shaft, T or FSSNG500 series for 100 thru 140 diam and SD3100 series thru to 300 diameter and either CSD series or AW solid housings above that. We propose Taconite sealing for all pulley applications. Shell: Our shell thickness calculation uses the thesis of Sitzwohl from Germany who investigated many failures of pulleys with belt wrap angles above and below 180 degrees and developed his now well proven theory which incorporates a correction factor (K1) dependent on the angle of belt wrap, where 180 degrees incurs the lowest K1 factor of 0.033 to a high of 0.13 which is incurred for a 70 degree wrap angle. We limit shell stress to less than 55Mpa at worst case run loads. End Discs: For most pulleys we use standard flat plate theory based on the transmitted bending moment. We limit end disc stress to less than 55Mpa at worst case run loads. For highly stressed pulleys where the diameter permits we use the Schmoltzi flexible “T” disc design. The larger diameters are required for this style end disc or the resultant stiffness basically results in a rigid end disc design. A sample of this design is attached. Couplings: Our coupling designs are based on the SKF oil injected method and we recommend tapered joints for better maintenance procedures. See sample attached. Manufacturers of quality engineered components for Industry using the latest CNC machining technology DBCT Pulley design check.xls P92 Run Date: 18/11/2006 TEFCO PULLEYS Page: Liveshaft Pulley "Design Sheet" of Design PJB Checked DBCT 7X Coal Terminal upgrade PROJECT TEFCO REF: CONVEYOR REF: PULLEY REF: DBCT 7X Pulley Job 7313 Feeders BF5 & BF11 DRIVE P92 with installed power 1 X 110Kw Pulley Resolved load: Max 489.0 300.0 kN Pulley Resolved load: Run 489.0 300.0 kN Belt Wrap Angle 200 0 deg T1 200.0 kN ANGLE A1 200.0 kN 20 deg 2400 mm ANGLE A2 ( - ) 1.00 m/s T2 Lagging Thickness 12mm 1226 mm Lagging Type Razer 2650 mm Qty Drive Ends 3500 mm 1 Legth.CL Brg/CL Drive -TBC 110 Kw 1450 1480 R.P.M. Drive Mount -Cplg or Shaft Cplg Motor FLT @ Pulley 90 kN 68750 Yes Belt Tension T1: Start. Belt Tension T1: RUN Belt Entry Angle A1 Belt Tension T2: Start. Belt Tension T2: RUN Belt Exit Angle A2 Belt Width Belt speed Pulley Shell Diameter Pulley Face Width Bearing Housing Centres Installed Power Motor Speed Overhung load Brakes or Holdbacks Fitted Published Bolt Torque (Ma) Published Hub Pressure (Pn) Published Shaft Pressure (Pw) L/Assy Torque Service Factor Bearing Life Required Required Dynamic Capacity Bearing Size Select Spherical Allowable Shaft Defl'n L/2000 Allowable Defl'n @ Hub Allowable Defl'n @ Hub Allowable Stress @ Hub Allowable Stress @ Hub Allowable Stress @ Brg Allowable Stress @ Brg Allowable Stress @ Cplg Design Load "P" Max Design Load "P" Run C L C/L HUB D5 D4 D3 E D C LOCKING ASSEMBLY SELECTION Bending Moment (M) 156830 B/ Moment transferred 153474 B/ Moment transferred 153474 B/ Moment Ratio % 29% B/ Moment Ratio % 29% Bolt Torque to be used 550 930 Nm Hub Pressure Used (pn) 113 Mpa 67 Resultant Shaft Pressure (pw) 103 175 Mpa Actual Transmissable Torque 451 % 309892 BEARING SELECTION to ISO 281 60000 Hours Actual B10 Bearing Life 15433201 Bearing Dynamic Rating 4300 814 kN 23172 Brg Housing Designation SDD3172 SHAFT DESIGN TO AS1403 - using 4140 Grade 1.75 mm Actual Deflection @ Ctr 0.84 5.0 mins Actual Deflection @ Hub 2.8 5.0 mins Actual Deflection @ Hub 2.8 Actual Shaft Stress @ Hub 214 360 Mpa Actual Shaft Stress @ Hub 360 Mpa 214 Actual Shaft Stress @ Brg 98 360 Mpa Actual Shaft Stress @ Brg 98 360 Mpa Actual Shaft Stress @ Drive 108 360 Mpa 244.5 KN Safety Factor used (Fs) 1.2 Shaft O/All Lgth 4386 244.5 KN Estimated Plly Assy. Mass 10226 C/L BRG Mass moment of inertia 1442.6 Shaft dia D5 390 D1 E Shaft Step Length 1120 T3015 380 x 475 2420 mm 524000 Nm Locking Assembly Type Locking Assembly Size Hub centres Published Torque Rating (Mt) D2 B Allowable Shell Stress - Run Allowable Shell Stress - Start Min. Shell thickness - Run Allowable End Disc Run Stress End Disc thickness RUN DATE: 18-Nov-06 Using Tefco Design kN kN Deg Pulley Speed 15.3 R.P.M. Pulley Diam over lagging: 1250mm Ceramic Grade mm with shaft drive ext'n 340 Diam x 442Long Nm Shaft lgth CL Hsg to end756 Nm Nm Nm Nm Mpa Mpa Nm At Start Load At Start Load At Run Load At Start Load At Run Load Effective interference 0.456mm Stress raiser K@L/Assy 3.33 Hours At Run Load kN Tac Material with min UTS 800Mpa mm At Start Load mins At Run Load mins At Start Load Mpa At Run Load Mpa At Start Load Mpa At Run Load Mpa At Start Load Mpa At Run Load mm kg kgm2 D4 380 D 90 D3 380 C 236 D2 340 B 40 A SHELL DESIGN using SITZWOHL's THEORY Actual Shell Stress 22.5 Mpa Actual Shell Stress 22.5 Mpa Selected Shell Thickness 32 mm in Ctr END DISC DESIGN using FLAT PLATE THEORY Actual End Disk Stress 55 Mpa 19.6 Mpa Actual End Disk Stress 19.6 Mpa 150 mm 55 Mpa 69 Mpa 20.4 mm At Run Load At Start Load 32 mm at Edge At Run Load At Start Load D1 340 A 264 Tefco Schmoltzi Pulley Design.XLS Smoltzi Drive Run Date: 18/11/2006 TEFCO PULLEYS Page: "T" Type End Disc Liveshaft Pulley "Design Verification Sheet" PROJECT TEFCO REF: CONVEYOR REF: PULLEY REF: Belt Tension T1: Maximum Belt Tension T1: RUN Belt Entry Angle A1 Belt Tension T2: Maximum Belt Tension T2: RUN Belt Exit Angle A2 Belt Width Belt speed Pulley Shell Diameter Pulley Face Width Bearing Centres Installed Power Motor Speed Overhung load Brakes or Holdbacks Fitted Locking Assembly Type Locking Assembly Size Hub & L/Assembly centres Published Torque Rating (Mt) Published Bolt Torque (Ma) Published Hub Pressure (Pn) Published Shaft Pressure (Pw) L/Assy Torque Service Factor End Disc thickness (W2) End Disk thickness (W1) End Disk Hub Width (L2) L/Assy contact width (L1) Bore Diameter of Hub Radius Disc/Shell Radius Disc/Hub Diameter outside Hub (Ri) Diameter inside shell (Ra) Allowable End Disc Run Stress Actual Disk Stress Running Full Actual Disk Stress Starting Full At Hub inner Diameter At Hub outer Diameter Bearing Life Required Required Dynamic Capacity Bearing Size Selected Spherical Luan Wangzhuang Conveyor Project ACT Luan Wangzhuang Pulley quote 270105 Drift Dual DRIVE 2 x 500 Kw with installed power 2 X 500Kw Pulley Resolved load: Max 677.3 kN 441.0 kN Pulley Resolved load: Run 415.0 kN 651.3 kN Belt Wrap Angle 0 degrees 200 Deg T1 251.0 kN ANGLE A1 Pulley Speed 251.0 kN degrees 61.2 R.P.M. 20 1200 mm ANGLE A2 (-) 5.20 m/s T2 Lagging Thickness Pulley Diam. over Lagging 1624mm 1600 mm 12mm Lagging Type Ceramic Grade 1400 mm Razer Number of Drive Ends 1850 mm 2 Length.C/L Brg to C/L Drive 1000 Kw 1420 mm Drive Mount - Cplg or Shaft with shaft drive ext'n 280 Diam x 420Long 1480 R.P.M. CPLG Motor FLT @ Pulley 20 kN 78077 Nm Yes LOCKING ASSEMBLY SELECTION Bending Moment (M) At Maximum Load T3006 88459 Nm B/ Moment transferred At Maximum Load 76431 Nm 340 B/ Moment transferred At Run Load 1330 mm 73526 Nm 218000 Nm 35% B/ Moment Ratio % At Maximum Load B/ Moment Ratio % At Run Load 34% Bolt Torque to be used 500 Nm 690 Nm Hub Pressure Used (pn) 109 Mpa 79 Mpa Resultant Shaft Pressure (pw) Effective interference 0.319mm 136 Mpa 99 Mpa Actual Transmissable Torque Stress raiser K@L/Assy 2.37 202 % 157971 Nm "T" TYPE END DISC DESIGN using SCHMOLTZI's THEORY 29 mm 60 mm W2 80 mm 74 mm Shell I.D. 425 mm 20 mm 25 mm 700 mm W1 1518 mm 55 Mpa Hub O.D. 38 Mpa L1 Bore Diam 39 Mpa L2 END DISC HOOP STRESS CHECK using THICK WALL THEORY Effective Hub OD 129 Mpa 870 mm Von Mises stress When Starting Full 50 Mpa 181 Mpa BEARING SELECTION to ISO 281 Actual B10 Bearing Life At Run Full Load 553982 Hours 60000 Hours Bearing Dynamic Rating 1643 kN 3200 kN Bearing Housing Designation SD3160 TAC 23160 SHAFT DESIGN TO AS1403 - using 0.93 5.0 5.0 270 270 270 270 270 338.6 Kn 325.6 Kn Allowable Shaft Deflection L/2000 Allowable Defl'n @ Hub Allowable Defl'n @ Hub Allowable Stress @ Hub Allowable Stress @ Hub Allowable Stress @ Brg Allowable Stress @ Brg Allowable Stress @ Cplg Design Load "P" Max Design Load "P" Run C L C/L HUB mm mins mins Mpa Mpa Mpa Mpa Mpa C/L BRG Actual Deflection @ Centre Actual Deflection @ Hub Actual Deflection @ Hub Actual Shaft Stress @ Hub Actual Shaft Stress @ Hub Actual Shaft Stress @ Brg Actual Shaft Stress @ Brg Actual Shaft Stress @ Cplg Safety Factor used (Fs) Estimated Shaft O/All Length Estimated Plly Assembly Mass Mass moment of inertia Shaft dia D5 D4 E D D3 Allowable Shell Stress - Run Allowable Shell Stress - Start Minimum Run Shell thickness C of Designer PJB Checked Run Date: 18-Nov-06 D2 D1 B A 55 Mpa 69 Mpa 38.1 mm Shaft Step Length 1045 Grade 0.26 1.6 1.7 140 153 139 152 201 1.2 3012 6397 2130 D5 350 E 615 Material with min UTS 600Mpa mm mins mins Mpa Mpa Mpa Mpa Mpa At Maximum Load At Run Load At Maximum Load At Run Full Load When Starting Full At Run Full Load When Starting Full At Run Load mm kg kgm2 D4 340 D 50 SHELL DESIGN using SITZWOHL's THEORY Actual Shell Stress 47.6 Mpa Actual Shell Stress 49.4 Mpa Selected Shell Thickness 41 mm D3 340 C -5 D2 280 B 50 At Run Full Load When Starting Full In Pulley Centre D1 280 A 215 Rigid Coupling Taper Design Rev2.xls CPLG Run Date: 4/10/2006 TEFCO ENGINEERING PTY.LTD. Page: of COUPLING DESIGN CHECK SHEET USING SKF METHOD PJB DESIGNER COUPLING STYLE OIL INJECTED TAPERED BORE PROJECT NAME: TEFCO JOB or QUOTE No.: Ashton Maingate 7195 CONVEYOR REF: Maingate 1 CHECKED 4-Oct-06 DATE INPUT DATA INSTALLED POWER GEARBOX OUTPUT SPEED START UP FACTOR OVERHUNG LOAD G/BOX C/L TO COUPLING C/L BORE DIA ( NOMINAL) HUB OUTSIDE DIAMETER CONTACT WIDTH FLANGE DIAM FLANGE THICKNESS BOLT DIAMETER ( Grade 10.9 ) BOLT QUANTITY COUPLING HALF MASS 400 78.1 1.3 30 750 220 330 280 490 42 M30 20 141 INPUT DATA FROM DIAGRAM 17 FRICTION ZONE (nL) m BENDING ZONE RATIO ( Z ) NOTE: Z Preferably to exceed 3.0 kW RPM Kn mm mm mm mm mm mm mm Kg CALCULATED VALUES FOR DIAGRAM 17 BENDING MOMENT FRICTION 0.28 Ce 0.67 nd 2.39 MATERIAL INFORMATION COUPLING MATERIAL GRADE 1045 600 MPa MATERIAL YIELD MINIMUM REQUIRED SAFETY FACTOR @ START 2.0 YOUNGS MODULUS (E) 210000 Pa FRICTION COEFFICIENT 0.14 SURFACE FINISH 0.005 mm 220 25 180 0.399 0.278 0.121 65258 22500 43.8 0.165 0.203 53.8 2.46 BORE & SHAFT MACHINING TOLERANCES Based on U6 bore / h7 shaft interference relationship SHAFT DIAM - Large End (mm) SHAFT DIAM - Small End (mm) Upper Limit Lower Limit 220.000 210.667 219.954 210.621 Upper Limit Lower Limit mm deg C deg C mm mm mm EQUIVALENT STRESS @ MAXIMUM INTERFERENCE MAXIMUM INTERFERENCE 0.278 mm OUTER HUB 237 MPa INNER HUB 265 MPa MAXIMUM PRESSURE 74 MPa MIN. MATERIAL YEILD REQUIRED 264 MPa ACTUAL TORQUE RANGE MINIMUM TORQUE CAPABILITY MAXIMUM TORQUE CAPABILITY RESULTS DUE TO BENDING MOMENT CHANGE OF PRESSURE FRICTION ZONE WIDTH (L) 160414 Nm 219680 Nm 3.01 MPa 64.32 BOLTED FLANGE TRANSMISSIBLE TORQUE-10.9 BOLT TF TORQUE CAPABILITY 187336 Nm FRICTION COEFFICIENT USED 0.25 2.87 At Start RESULTING SAFETY FACTOR 280 10 42 98 110 430 Bolt PCD R12 1/4"BSP 490 Flange Dia 310(H6/h6)Spigot Dia 210.418 Bore Diam Nm Nm MPa mm mm MPa At Start COUPLING BORE - Large End (mm) 219.751 219.722 COUPLING BORE - Small End (mm) 210.418 210.389 SHAFT TAPER LENGTH 280 mm DRIVE UP LENGTH (min and max) 6.1mm 8.3mm EQUIVALENT STRESS @ MINIMUM INTERFERENCE MINIMUM INTERFERENCE 0.203 mm OUTER HUB 173 MPa INNER HUB 194 MPa MINIMUM PRESSURE 54 MPa 0.7 0.4 4.35 SHRINK FITTING TEMPERATURE BORE DIAM BASE TEMPERATURE HEAT COUPLING TO TEMPERATURE BORE GROWTH MAXIMUM INTERFERENCE FITTING CLEARANCE (MIN 0.1mm) OUTPUT DATA TORQUE ( @ START ) BENDING MOMENT (Mb) REQUIRED CONTACT PRESSURE REQUIRED INTERFERENCE CHOSEN INTERFERENCE RESULTING CONTACT PRESSURE MIN RESULTING FIT SAFETY FACTOR 330 Hub Diam 219.751 Bore Diam
